In office buildings it is common to use modular wall systems, rather than walls made of building materials, to permit flexibility in rearranging the room or cubicle configurations of the offices. For greatest flexibility, use is made of system furniture wall panels, which are normally not fastened in any fashion to the building, and which derive their stability from adjacent similar panels and furniture. Heretofore, such use has been limited to providing cubicle-type enclosures, these may typically be four feet (counter high), seven feet (head high), or eight feet, or so, in height. However, they are not readily utilized for closed offices because of irregularities in the building structure which precludes manufacture of prefabricated, furniture-type wall structures which can be used for a complete ceiling to floor arrangement. Of course, other semi-custom partitioning systems may be utilized to provide modular walls of various sizes, as is known in the art. Examples of these are shown in U.S. Pat. Nos. 4,018,020; 3,593,475; and 4,086,734; and UK application 2,049,013. While these are easy to assemble and generally utilize paneling which can be cut to the desired size and shape, thereby to accommodate the individual needs of each installation, they are difficult to take apart, and therefore do not serve as an adjunct to readily-movable system furniture wall paneling, which instead requires adjunctive ceiling panels (that is, panels between the top of the system furniture wall panel and the ceiling) that are fully demountable, in order to retain the versatility of the system furniture wall paneling.